1. Field of the Invention
The present invention relates to a watertight connector.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 2002-343492 discloses a watertight connector with a housing that has a plurality of cavities for accommodating female terminal fittings. A one-piece rubber plug is arranged at the rear of the cavities and has wire insertion holes that align respectively with the cavities. A holder is mounted behind the rubber plug and has terminal insertion openings that correspond respectively to the wire insertion holes. Each female terminal fitting is secured to the end of a wire and is inserted through a terminal insertion opening of the holder. The female terminal fitting then resiliently widens the wire insertion hole and penetrates the rubber plug. Finally, the female terminal fitting is pressed into the respective cavity. The rubber plug returns resiliently after the female terminal fitting has passed so that the inner surface of the wire insertion hole closely contacts the outer circumferential surface of the wire to provide sealing.
An ordinary female terminal fitting has a rectangular tubular main portion with a contact tongue therein. The wire extends back from the main portion of the female terminal fitting and has an outer diameter slightly smaller than dimensions of the outer shape of the main portion. The diameter of the wire insertion hole must be set to closely contact the outer circumferential surface of the wire. Dimensions of the outer shapes of the main portion are significantly larger than the diameter of the wire insertion hole if the female terminal fitting is large. Accordingly, the main portion of the female terminal fitting may not be easily insertable through the wire insertion hole. Forcible insertion of the main portion through the wire insertion hole can tear or break the rubber plug, and hence may deteriorate sealing performance.
The invention was developed in view of the above problem and an object thereof is to avoid a reduction in sealing performance caused by the breakage of a rubber plug.